Unit 3-C (C):Unit 3-C (C):Heritability and Heritability and

Molecular GeneticsMolecular GeneticsMr. McCormickMr. McCormickA.P. PsychologyA.P. Psychology

Do-NowDo-Now(In Journal)(In Journal)

How much of your How much of your behaviorbehavior do you do you attribute attribute to to biologybiology??

How much of your How much of your behaviorbehavior do you attribute to your do you attribute to your environmentenvironment??

Why?Why?

HeritabilityHeritability

Heritability:Heritability: The proportion of variation among individuals that The proportion of variation among individuals that

we can attribute to geneswe can attribute to genes Varies, depending on populations and environments Varies, depending on populations and environments

being studiedbeing studied Measured from 0-1:Measured from 0-1:

0 [0%] 0 [0%] (low heritability): (low heritability): Influenced by Influenced by environmentenvironment 1 [100%] 1 [100%] (high heritability): (high heritability): Influenced by Influenced by genesgenes

E.g.: If the E.g.: If the heritabilityheritability of of intelligence intelligence in a given in a given population/environment is population/environment is 40% 40% (moderately low(moderately low), then genetic ), then genetic influence explains 40% of differences in intelligence among that influence explains 40% of differences in intelligence among that specific populationspecific population

Herit: Herit: InheritInherit Ability: Ability: CapabilityCapability

Heritability:Heritability:Genetic or Environmental Genetic or Environmental

Differences?Differences? Observe the image of Observe the image of “Plant Heritability”“Plant Heritability”

What can explain What can explain variations of height variations of height among among plants grown in theplants grown in the left left flower pot?flower pot?

Describe the Describe the Heritability Heritability (High/Low) (High/Low) of of height variations height variations among plants grown in the among plants grown in the leftleft flower pot. flower pot.

What can explainWhat can explain variations of height variations of height among among plants grown in theplants grown in the right right flower pot?flower pot?

Describe the Describe the Heritability Heritability (High/Low) (High/Low) of of height variations height variations among plants grown in the among plants grown in the rightright flower pot. flower pot.

What can explain What can explain variations of height variations of height among among plants grown in plants grown in bothboth the the leftleft and and rightright flower pots? flower pots?

Describe the Describe the Heritability Heritability (High/Low) (High/Low) of of height variations height variations among plants grown in among plants grown in bothboth the the leftleft and and right right flower pots.flower pots.

HeritabilityHeritability

Can you think of a Can you think of a real-life examplereal-life example, , in which in which differencesdifferences within a within a specific specific populationpopulation were highly due were highly due to to environmentenvironment (low heritability)(low heritability)??

Can you think of a Can you think of a real-life examplereal-life example, , in which in which differencesdifferences within a within a specific specific populationpopulation were highly due were highly due to to genetics genetics (high heritability)(high heritability)??

Nature Vs. NurtureNature Vs. Nurture

GenesGenes and and environmentsenvironments work together in work together in influencing human thought and behavior:influencing human thought and behavior:

GenesGenes may may predisposepredispose individuals to various individuals to various physical physical and and psychological traitspsychological traits, though one’s , though one’s environmentenvironment maymay affect affect the extent to which these the extent to which these traits developtraits develop

Interaction:Interaction: The interplay that occurs when one factor The interplay that occurs when one factor

(heredity) affects another factor (environment)(heredity) affects another factor (environment) E.g. Someone with a predisposition to aggression E.g. Someone with a predisposition to aggression

may elicit others to treat them more defensivelymay elicit others to treat them more defensively

Nature Vs. NurtureNature Vs. Nurture

Can you think of an Can you think of an

example example of an of an interactioninteraction between a between a “Nature” “Nature” factor and a factor and a

“Nurture” “Nurture” factor?factor?

Molecular GeneticsMolecular Genetics

Molecular Genetics:Molecular Genetics:

The subfield of biology that The subfield of biology that studies the molecular studies the molecular structure and function of structure and function of genesgenes

““Bottom Up” approach to Bottom Up” approach to understanding biopsychologyunderstanding biopsychology

E.g. Identifying genes that E.g. Identifying genes that influence one’s introversion influence one’s introversion vs. extroversionvs. extroversion

HomeworkHomework

Chapter 4 Quiz: Chapter 4 Quiz: “Nature, Nurture, and “Nature, Nurture, and Human Diversity”Human Diversity”

Unit 3 Test: Unit 3 Test: “Biological Bases of Behavior”“Biological Bases of Behavior”

Chapter 6 Outline: Chapter 6 Outline: “Sensation and “Sensation and Perception”Perception”

Unit 3 Project: Unit 3 Project: “3-D Brain Model”“3-D Brain Model”